I dont know about you, but like a high school senior that just eked out a seventy on their math test, Im happy enough with that calculus
This is actually quite powerful with a card like Sneak Attack: You can cheat in something big, say, Cityscape Leveler, then attack
Looking at early results, this doesnt look to be changing, either, but Pro Tour Final Fantasy is just a few days away
In the rare case where enough -1/-1 counters are put on Aerith Gainsborough at the same time to make its toughness 0 or less, the number of +1/+1 counters on it before it got those -1/-1 counters will be used to determine the value of X in Aerith Gainsborough's third ability
So, all creatures that cost one mana, then all creatures that cost two, and so on
And its incredibly cheap for all this versatility